Electrochemical Formation of Germanene: pH 4.5
Electrochemical Formation of Germanene: pH 4.5
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DOI：
10.1149/2.1221707jes
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发表时间：
2017-05
影响因子：
3.9
通讯作者：
Maria Ledina;N. Bui;Xuehai Liang;Youn-Geun Kim;Jin-Young Jung;Brian R. Perdue;C. Tsang;J. Drnec;F. Carlá;M. Soriaga;T. Reber;J. Stickney
中科院分区：
文献类型：
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作者：
Maria Ledina;N. Bui;Xuehai Liang;Youn-Geun Kim;Jin-Young Jung;Brian R. Perdue;C. Tsang;J. Drnec;F. Carlá;M. Soriaga;T. Reber;J. Stickney
锗烷烯是Ge的单层同素异形体，具有类似于石墨烯的蜂窝结构。本报告涉及锗烯在pH 4.5的溶液中的电化学形成。采用电化学扫描隧道显微镜（EC-STM）、伏安法、库仑法、表面X射线衍射（SXRD）和拉曼光谱等方法研究了锗烯在Au（111）平台上的电沉积。Ge的沉积动力学缓慢，在2-3个单层后停止。EC-STM显示了具有菱形晶胞的蜂窝（HC）结构，边长为0.44 ± 0.02 nm，非常接近文献中对锗烯的预测。理想情况下，HC结构是一个连续的薄片，每个孔周围有六个Ge原子。然而，在这项研究中，只观察到这种结构的小域，周围的缺陷。小的相干长度和多个旋转域使得难以用表面X射线衍射直接观察。拉曼光谱被用来研究多层Ge沉积。在290 cm^（−1）附近的一个峰，预测对应于锗烯，在样品的一个特定区域观察到，而其余部分类似于非晶锗。锗烯的电化学研究表明，有限的稳定性时，暴露于氧气。
Germanene is a single layer allotrope of Ge, with a honeycomb structure similar to graphene. This report concerns the electrochemical formation of germanene in a pH 4.5 solution. The studies were performed using in situ Electrochemical Scanning Tunneling Microscopy (EC-STM), voltammetry, coulometry, surface X-ray diffraction (SXRD) and Raman spectroscopy to study germanene electrodeposition on Au(111) terraces. The deposition of Ge is kinetically slow and stops after 2–3 monolayers. EC-STM revealed a honeycomb (HC) structure with a rhombic unit cell, 0.44 ± 0.02 nm on a side, very close to that predicted for germanene in the literature. Ideally the HC structure is a continuous sheet, with six Ge atoms around each hole. However, only small domains, surrounded by defects, of this structure were observed in this study. The small coherence length and multiple rotations domains made direct observation with surface X-ray diffraction difficult. Raman spectroscopy was used to investigate the multi-layer Ge deposits. A peak near 290 cm^(−1), predicted to correspond to germanene, was observed on one particular area of the sample, while the rest resembled amorphous germanium. Electrochemical studies of germanene showed limited stability when exposed to oxygen.